DSL (digital subscriber line) is a technology for bringing high-bandwidth information to homes and small businesses over ordinary copper telephone lines. A DSL line can simultaneously carry both data and voice signals. The data portion of the line may be continuously available to the user, making DSL an “always-on” connection. Special digital hardware attached to both ends of the line allows data transmission over the wires at far greater speed than standard analog 56 kilobyte (K) modems.
DSL is offered to users by DSL providers. DSL providers connect user DSL modems, through a digital subscriber line, to a central office. Typically, the distance between the user and the central office must be less than a certain distance, such as about four miles, for the DSL connection to operate properly. At the central office, signals from the DSL user may be packetized and transmitted to a larger network, such as an asynchronous transfer mode (ATM) network that connects to an Internet Service Provider (ISP).
DSL providers may operate a number of DSL circuits which are subject to congestion based on the bandwidth needs of the customers connected to the DSL circuits. For example, legacy DSL circuits may share a single DS3 link (operating at 45 Megabits per second (Mbps)) between “1,296” customers. Unfortunately, the bandwidth available to individual customers in such legacy DSL circuits is quickly becoming insufficient.